Summary of the invention
One of purpose of the present invention is to provide a kind of package structure for LED and preparation method thereof, to overcome the caused problem of above-mentioned known method.
For reaching above-mentioned purpose, the invention provides a kind of method of making package structure for LED, it includes:
Substrate and a plurality of light-emitting diode chip for backlight unit are provided, and make these light-emitting diode chip for backlight unit solid respectively brilliant on this substrate;
On this substrate and these light-emitting diode chip for backlight unit, form fluorescence coating; And
This fluorescence coating of patterning makes this fluorescence coating become a plurality of fluorescent colloids, and these fluorescent colloids are arranged at these light-emitting diode chip for backlight unit top, makes respectively that this fluorescent colloid has a plurality of light perforation, and respectively this light perforation vertically runs through respectively this fluorescent colloid.
For reaching above-mentioned purpose, the present invention provides a kind of package structure for LED in addition, and it includes:
Substrate;
At least one light-emitting diode chip for backlight unit is fixed on this substrate; And
At least one fluorescent colloid is arranged on this substrate and these light-emitting diode chip for backlight unit, and this fluorescent colloid has a plurality of light perforation, and respectively this light perforation vertically runs through respectively this fluorescent colloid.
But form fluorescent colloid in package structure for LED usability luminescent material of the present invention, therefore can utilize semiconductor technology to carry out batch manufacturing and the patterning step of fluorescent colloid.Because fluorescent colloid of the present invention has a plurality of light perforation, therefore can adjust the fluorescent material distribution density of fluorescent colloid or fluorescence coating effectively, again to promote the optical effect of package structure for LED.
Description of drawings
What Fig. 1 illustrated is the gluing process schematic diagram of known formation LED encapsulation construction.
Fig. 2 a-2b, 3a-3b, 4a-4b, 5a-5c, 6a-6b make the schematic diagram of the method preferred embodiment of package structure for LED for the present invention.
Fig. 7 and Fig. 8 make the method schematic diagram of package structure for LED for another preferred embodiment of the present invention.
Fig. 9 a-9b, 10a-10b, 11a-11b make the schematic diagram of the method for package structure for LED for the another preferred embodiment of the present invention.
Description of reference numerals
1: LED encapsulation construction 2: pedestal
3: lead frame 4: base plate for packaging
5: light-emitting diode chip for backlight unit 6: packaging adhesive material
7: bonding wire 8: spot gluing equipment
30: substrate 32: crystal bonding area
36: through hole 38: lead
40: light-emitting diode chip for backlight unit 46: the photoresists material
48: fluorescent material 50: flat structures
52: contact hole 54: lead
56: fluorescent colloid 57: the light perforation
58: seal ring-like pattern 62: colloid
64: fluorescence coating 66: light-emitting diode chip for backlight unit
70: fluorescence membrane 72: fluorescent material
74: photosensitive dry film 76: fluorescence coating
U: unit
Embodiment
For making the general technical staff of the technical field of the invention can further understand the present invention, hereinafter the spy enumerates a plurality of preferred embodiment of the present invention, and cooperates institute's accompanying drawing, describes constitution content of the present invention and the effect desiring to reach in detail.
Please refer to Fig. 2 a-2b, 3a-3b, 4a-4b, 5a-5c, 6a-6b.Fig. 2 a to Fig. 6 b makes the schematic diagram of the method preferred embodiment of package structure for LED for the present invention, and wherein Fig. 2 a to Fig. 6 a is a schematic top plan view, and Fig. 2 b to Fig. 6 b is a generalized section, and Fig. 5 c is the schematic top plan view of whole base plate 30.Shown in Fig. 2 a and Fig. 2 b, at first provide substrate 30 and a plurality of light-emitting diode chip for backlight unit 40.Wherein, substrate 30 definition have a plurality of unit (unit) U, respectively in order to each light-emitting diode chip for backlight unit 40 to be set.Substrate 30 can be semiconductor substrate, for example is preferably silicon substrate, GaAs substrate or other has excellent heat conductivity, is fit to batch produce and be compatible to the substrate of semiconductor technology.The crystal bonding area 32 that can have a plurality of depressions in the upper surface of substrate 30.The degree of depth of crystal bonding area 32 preferably can be approaching with the height of the light-emitting diode chip for backlight unit of subsequent fixed in it, and its degree of depth be between several microns between the tens of micron, for example be preferably between 10 to 50 microns, but not as limit.Because the degree of depth of crystal bonding area 32 and the height of light-emitting diode chip for backlight unit 40 are approaching, therefore the upper surface in solid brilliant metacoxal plate 30 and light-emitting diode chip for backlight unit 40 can roughly be positioned at same plane.
The present invention can take any suitable electric connection mode to be beneficial to light-emitting diode chip for backlight unit externally to electrically connect, yet because adoptable electric connection mode is numerous, so its detailed connected mode clearly is not illustrated among the figure.For example can utilize the lead-in wire mode to be connected to lead on the substrate 30 (figure does not show), to utilize and cover crystal type and be connected to lead (figure does not show) on the substrate 30, use conducting resinl material, eutectic to engage (eutectic bonding) or alternate manner is reached by soldering projection by bonding wire, and the lead 38 of substrate 30 can be connected to the lower surface of substrate 30 via the through hole 36 of substrate 30, but is not limited thereto.In addition, light-emitting diode chip for backlight unit 40 of the present invention can adopt various types of light-emitting diode chip for backlight unit, for example selects vertical-type chip or horizontal type chip for use.
Shown in Fig. 3 a and Fig. 3 b, then optionally on substrate 30 and light-emitting diode chip for backlight unit 40, form the flat structures 50 of printing opacity.Flat structures 50 has dielectric property and inserts the outside of light-emitting diode chip for backlight unit 40 and the space between the crystal bonding area 32, makes the substrate 30 and the upper surface of light-emitting diode chip for backlight unit 40 form complete tabular surface, helps the making of subsequent film thus.Can comprise a plurality of contacts hole 52 in addition in the flat structures 50,, but be not limited thereto for can outwards being electrically connected of each light-emitting diode chip for backlight unit 40 via contact hole 52.
Shown in Fig. 4 a and Fig. 4 b, thereafter, optionally on flat structures 50, form lead 54 in addition, and lead 54 is inserted contact hole 52, electrically connect thus.Then can utilize spin coating process on substrate 30, light-emitting diode chip for backlight unit 40 and flat structures 50, to form fluorescence coating 64, fluorescence coating 50 includes photoresists material 46 and is mixed in the photoresists material 46 with fluorescent material 48, for example includes the photosensitive material that mixes fluorescent material 48.Be noted that fluorescent material 48 is actually quite small particulate, for the clear distributing position that shows fluorescence coating 50, so fluorescent material 48 is not shown in the vertical view.Wherein, photoresists material 46 can comprise can form behind the photosensitive resin irradiations such as (photosensitive resin) behind link or the irradiation can cracking material, and preferably has good light permeability, and fluorescent material can comprise the material of yttrium aluminium garnet fluorescent powder convertible wavelength of light such as (yttrium aluminum garnet are called for short YAG).
Shown in Fig. 5 a and Fig. 5 b, utilize exposure and the aforementioned fluorescence coating 64 of developing process patterning afterwards, make fluorescence coating 64 become a plurality of fluorescent colloids 56, and can make each fluorescent colloid 56 have a plurality of light perforation 57 simultaneously.Each fluorescent colloid 56 correspondence respectively is arranged at each light-emitting diode chip for backlight unit 40 top.Each light perforation 57 can be uniformly distributed in each fluorescent colloid 56, and can vertically run through each fluorescent colloid 56, with the flat structures 50 of exposure fluorescent colloid 56 belows or the part surface of light-emitting diode chip for backlight unit 40.Because the part of light perforation 57 is not had fluorescent material 48, so the existence of light perforation 57 can reduce this regional fluorescent material 48 quantity, uses to change the colour temperature that package structure for LED presented.Wherein the light of each fluorescent colloid 56 57 shared areas of boring a hole can be adjusted according to designs such as the brightness of each light-emitting diode chip for backlight unit 40 and product demands, are preferably 5% to 30% of the area that accounts for each fluorescent colloid 56.
The effect of fluorescent colloid 56 is that the part light that light-emitting diode chip for backlight unit 40 is produced converts the light of another color to, for example the light-emitting diode chip for backlight unit 40 of present embodiment can be blue LED chip, therefore fluorescent colloid 56 can use the fluorescent material (yellow phosphor) that can produce gold-tinted, and then produces white light by blue light and gold-tinted mixed light.Perhaps, utilize the ultraviolet light-emitting diodes chip to excite blue light, green glow and red light fluorescent powder.Be noted that the material and the generation type of fluorescent colloid 56 are not exceeded with present embodiment.
Be noted that the shape of the light perforation 57 of each fluorescent colloid 56, size, the shared gross area, the density and the position of distribution all can be adjusted according to the distribution density and the product demand of fluorescent material 48.Encapsulating structure with blue light-emitting diode is an example; for utilizing the formed fluorescence coating 64 of spin coating process; not having light when fluorescent colloid 56 bores a hole 57 the time; gold-tinted fluorescent material 48 density that are positioned at the middle section of substrate 30 can be come highly than gold-tinted fluorescent material 48 density of the fringe region that is positioned at substrate 30 usually; therefore the gold-tinted tone that package structure for LED presented that is positioned at the middle section of substrate 30 may be stronger than the gold-tinted tone that package structure for LED presented of the fringe region that is positioned at substrate 30, causes same series-produced package structure for LED but to send in various degree colour temperature.Therefore, the present invention can be after forming fluorescence coating 64, measure the colour temperature or the brightness that are presented on arbitrary substrate 30, then compare the similarities and differences between measurement and the required product specification that presents, utilize the result who compares to design the layout of light perforation 57 again, utilize being provided with of light perforation 57 to regulate.Shown in Fig. 5 c, for example make the light of middle section of the substrate 30 57 opening ratios of boring a hole to come highly than the light 57 opening ratios of boring a hole of the fringe region of substrate 30.Perhaps; when the surface that substrate 30, light-emitting diode chip for backlight unit 40 and flat structures 50 are constituted has recess; fluorescent material 48 density of recess usually can be higher than smooth place or prominence; therefore the present invention can be provided with the light perforation 57 of higher opening ratio in recess, with as balance.
In addition, the present invention can form the ring-like pattern 58 of a plurality of sealings on flat structures 50, respectively around each crystal bonding area 32.Seal ring-like pattern 58 and have certain height, for example several microns, its role is to keep the surface tension of the colloid of follow-up formation, make it keep the effect of hemisphere shape and then performance optical lens.In the present embodiment, seal ring-like pattern 58 and can use identical photosensitive material, and used simplification technology, but method of the present invention is not as limit by forming with exposure and developing process with fluorescent colloid 56.
Shown in Fig. 6 a and Fig. 6 b, then carry out gluing process, on the fluorescent colloid 56 of each unit U, form colloid 62 respectively, and colloid 62 can be kept its surface tension by the existence of sealing ring-like pattern 58, formation hemisphere shape.Colloid 62 can form optical lens (lens) after curing, utilize cutting technique can produce a plurality of package structure for LED at last again.
In previous embodiment, fluorescence coating 64 rotary coating are on the surface of flat structures 50, because the flat characteristic of flat structures 50 makes photoresists material 46 and fluorescent material 48 can successfully utilize spin coating process to form uniform fluorescence coating 64.In other embodiment, the present invention also can not comprise flat structures 50, and makes photoresists material 46 and fluorescent material 48 can be spun on smooth surface by alternate manner.Please refer to Fig. 7 and Fig. 8.Fig. 7 and Fig. 8 are the method schematic diagram of another preferred embodiment making package structure for LED of the present invention, and wherein Fig. 7 is a schematic top plan view, and Fig. 8 is a generalized section.As Fig. 7 and shown in Figure 8, make light-emitting diode chip for backlight unit 66 be placed in crystal bonding area 32 after, light-emitting diode chip for backlight unit 66 end faces are rough identical with substrate 30 apical side heights, utilize spin coating process and Patternized technique again and form the fluorescent colloid 56 with light perforation 57.Wherein, light-emitting diode chip for backlight unit 66 can adopt variety of way to form the approach of external electrical connection, and package structure for LED can comprise other element or the retes that can promote production reliability or optics benefit in addition, yet its detailed electrical connection state, other elements or rete are not illustrated among the figure in this omission.
Because but package structure for LED usability luminescent material of the present invention forms fluorescent colloid, therefore can utilize semiconductor technology to carry out batch manufacturing and the patterning step of fluorescent colloid, significantly shorten the process time of package structure for LED, make process efficiency heighten.Again because the present invention can utilize the patterning step of fluorescent colloid to form the light perforation in the lump, therefore can be accurately and adjust the fluorescent material distribution density of fluorescent colloid easily, to promote the optical effect of package structure for LED, controlled the package structure for LED of being produced and can be sent identical or close colour temperature, perhaps also can be especially at the package structure for LED of same batch of production and adjust in various degree colour temperature.
Except can utilizing spin coating process and Patternized technique to come batch to make the uniform fluorescence coating, the present invention also can utilize mode that laser prints and batch produce uniform fluorescence coating.Please refer to Fig. 9 a-9b, 10a-10b, 11a-11b.Fig. 9 a to Figure 11 b makes the schematic diagram of the method for package structure for LED for the another preferred embodiment of the present invention, and wherein Fig. 9 a to Figure 11 a is the schematic top plan view of fluorescence membrane, and Fig. 9 b to Figure 11 b figure is the generalized section of fluorescence membrane.Shown in Fig. 9 a and Fig. 9 b, at first provide substrate 30 and a plurality of light-emitting diode chip for backlight unit 40.Wherein, substrate 30 definition have a plurality of unit U, respectively in order to each light-emitting diode chip for backlight unit 40 to be set.The crystal bonding area 32 that can have a plurality of depressions in the upper surface of substrate 30.The degree of depth of crystal bonding area 32 preferably can be approaching with the height of the light-emitting diode chip for backlight unit of subsequent fixed in it, but be not limited thereto.The flat structures 50 that on substrate 30 and light-emitting diode chip for backlight unit 40, optionally comprises printing opacity.Flat structures 50 has dielectric property and inserts the outside of light-emitting diode chip for backlight unit 40 and the space between the crystal bonding area 32, makes the substrate 30 and the upper surface of light-emitting diode chip for backlight unit 40 form complete tabular surface., in addition optionally in flat structures 50 on form lead 54, and lead 54 is inserted contact hole 52, electrically connect thus thereafter.
Shown in Figure 10 a and Figure 10 b, then utilize at least one laser technology of prining to form fluorescence membrane 70, wherein fluorescence membrane 70 includes fluorescent material 72.For instance, the generation type of fluorescence membrane 70 can utilize main charging rotating shaft that static is projected on photosensitive drums or the sensitization band earlier, again according to the predetermined pattern of required formation and with Electrostatic Absorption fluorescent material 72, then the fluorescent material 72 that presents predetermined pattern is transferred on the photosensitive dry film 74, to form required fluorescence membrane 70.
Because the laser characteristic of prining, analysing and observe sight, the fluorescent material 72 of single fluorescence membrane 70 is monolayer alignment vertical stacking not; To overlook sight, the print resolution of technology of laser can reach about 50 microns, even littler, therefore can control the arranged evenly of fluorescent material 72 and forms any predetermined pattern, and not limited to by Figure 10 b, and then also can control fluorescent material 72 density of arbitrary region.For instance, fluorescent material 72 can be evenly distributed on the whole fluorescence membrane 70, or only on the crystal bonding area 32 corresponding to substrate 30.And in other embodiment; with regard to single package structure for LED; luminous intensity directly over the light-emitting diode chip for backlight unit 40 usually can be bigger than the luminous intensity around the light-emitting diode chip for backlight unit 40; therefore fluorescence membrane 70 can be bigger corresponding to 72 density of the fluorescent material directly over the light-emitting diode chip for backlight unit 40, and can be smaller corresponding to fluorescent material 72 density around the light-emitting diode chip for backlight unit 40.
Shown in Figure 11 a and Figure 11 b, utilize heat pressing process that the fluorescent material 72 of fluorescence membrane 70 is transferred on the light-emitting diode chip for backlight unit 40 thereafter and form fluorescence coating 76.In view of the above, the fluorescent material 72 of single fluorescence coating 76 also can be monolayer alignment and vertical stacking not, and fluorescent material 72 density of arbitrary region also can obtain accurate control on the light-emitting diode chip for backlight unit 40.
In other embodiment of the present invention, print technology and aforementioned transfer step of aforementioned laser can be carried out repeatedly, to form multilayer fluorescence coating 76 on light-emitting diode chip for backlight unit 40.The laser technology of prining helps small fluorescent material 72 configurations on the adjacent or lap position of accurately configuration, arranges by atomic thin pattern and density and makes up utilization, can create the colour temperature that naked eyes seem suitable homogeneous.
In sum, because but package structure for LED usability luminescent material of the present invention forms fluorescent colloid or fluorescence coating, therefore can utilize semiconductor technology to carry out batch manufacturing of fluorescent colloid or fluorescence coating, effectively promote the process efficiency of package structure for LED.In addition, because the present invention can utilize exposure and developing process or the laser technology of prining accurately and easily to adjust the fluorescent material distribution density of fluorescent colloid or fluorescence coating, therefore can adjust the optical effect of package structure for LED exactly.
The above only is the preferred embodiments of the present invention, and all equivalent variations and modifications of doing according to claim of the present invention all should belong to covering scope of the present invention.